The present invention relates to a new and distinct variety of Buddleja (butterfly bush) grown as an ornamental shrub for home and commercial landscapes. Butterfly bush is typically grown for its attractive, fragrant flowers that are borne throughout the growing season.
The new and distinct variety of butterfly bush resulted from a formal breeding program established by the inventors in Raleigh, N.C., United States. One of the objectives of the breeding program was to develop a very dwarf, spreading Buddleja with purple-pink (lilac color) flowers. ‘Lilac Chip’ was selected at a research station in Jackson Springs, N.C. in 2006 from a population of 343 seedling progeny derived from a hand pollinated cross of ‘Blue Chip’ (female parent; NCSU variety tested as NC2004-9, U.S. Plant Pat. No. 19,991×‘Miss Molly’ (male parent; NCSU variety tested as NC2005-8, U.S. Plant Pat. No. 23,425) made in 2005 in Raleigh, N.C. ‘Blue Chip’ is a complex hybrid containing 3 different species and one botanical variety of Buddleja (B. davidii, B. davidii var. nanhoensis, B. lindleyana, and B. globosa). ‘Miss Molly’, the other parent of ‘Lilac Chip’, is a hybrid of ‘Miss Ruby’ (U.S. Plant Pat. No. 19,950)×‘Attraction’. ‘Miss Ruby’ was derived from hybridization of ‘White Ball’×‘Attraction’. ‘Attraction’ was derived as an open-pollinated seedling of ‘Honeycomb’, which is a hybrid of B. globosa×B. davidii. ‘Nanho Purple’ is a variety derived from Buddleja davidii var. nanhoensis. ‘White Ball’ is a complex hybrid, presumably containing B. davidii and B. fallowiana. The pedigree of ‘Lilac Chip’ is shown in Table 1. Of all the parents used in the development of ‘Lilac Chip’, the varieties ‘Blue Chip’, ‘Miss Molly’, ‘Miss Ruby’, ‘Attraction’, ‘White Ball’, ‘Nanho Purple’, and ‘Honeycomb’, and the species Buddleja lindleyana are available in commerce.
The seeds resulting from the 2005 controlled hybridization process were harvested in fall of 2005 and germinated in a greenhouse in Raleigh, N.C. in the winter of 2006. The resulting 351 seedlings were planted in field trials in spring of 2006 at a research station in Jackson Springs, N.C. These plants flowered in summer 2006, and one plant, designated NC2006-6, was selected for its very dwarf plant size, spreading habit, attractive lilac-colored flowers, and lack of seed set (very low female fertility). This original plant demonstrated characteristics identical to those subsequently expressed on other plants when propagated from stem cuttings. This single plant is the subject of the present invention Buddleja ‘Lilac Chip’.
TABLE 1Pedigree of Buddleja ‘Lilac Chip’.
The distinguishing traits of ‘Lilac Chip’ are very dwarf plant size, spreading growth habit, gray-green leaf color, attractive lilac-colored flowers, male sterility, and very low female fertility. Ideal cultural conditions for ‘Lilac Chip’ include well-drained soil, full sun, and moderate moisture. ‘Lilac Chip’ exhibits no serious pest or disease problems known to the inventors, except for occasional spider mite infestation during periods of hot, dry weather.
The closest comparison known to the inventors are the varieties ‘Blue Chip’ (U.S. Plant Pat. No. 19,991), and ‘White Ball’ (non-patented). Plants and flowers of this new variety differ from ‘Blue Chip’. In direct comparisons of ‘Lilac Chip’ and ‘Blue Chip’ in the inventor's experimental trials, plants of ‘Lilac Chip’ are more compact, and have purplish-pink flowers, compared to the blue flowers of ‘Blue Chip’. In replicated trials of 10 plants of both varieties, two-year-old unpruned plants of ‘Lilac Chip’ attained a height and spread of 40.5 and 74.6 cm, respectively (height/width ratio=0.54), after two years of growth. Plants of ‘Blue Chip’ attained a height and spread of 79.8 cm and 126.3 cm (height/width ratio=0.64), respectively. ‘Lilac Chip’ is distinctly different from ‘White Ball’. In direct comparisons of ‘Lilac Chip’ and ‘White Ball’ in the inventor's experimental trials, plants of ‘Lilac Chip’ are consistently more spreading as compared to the globose architecture of ‘White Ball’. ‘Lilac Chip’ is shorter in height and has purplish/pink flowers as compared to the white flowers of ‘White Ball’.
The inventors conducted the first asexual propagation of ‘Lilac Chip’ in fall 2006 in Raleigh, N.C., and ‘Lilac Chip’ has subsequently been propagated in the same location in years 2008, and 2009. In all cases, the original plant selection was propagated asexually by softwood to semi-hardwood stem cuttings. Such cuttings root readily under mist in about 14 to 21 days, and resume normal growth. Ten plants derived from stem cuttings of the variety were established in experimental test plots in Jackson Springs, N.C. in 2007. During all asexual propagation, the characteristics of the original plant have been maintained. Plants derived from stem cuttings exhibit characteristics identical to those of the original plant, and no aberrant phenotypes have appeared.
Test plantings and performance evaluation over six years at a research station in Jackson Springs, N.C. demonstrate this variety to be relatively consistent in its characteristics even under the different growing conditions associated with yearly climatic variation.
Plants of the new variety are very dwarf after establishment in the field, being less vigorous and more dwarf than most cultivars of butterfly bush in commerce. Young plants have averaged about 20.2 cm of height growth per year. Plants are spreading in growth habit. Flowering occurs in the first year of growth on newly formed wood. The inflorescence is a panicle, and shows a purplish-pink flower color. Flowering usually begins in early June in Jackson Springs, N.C., and continues throughout the growing season until the first freeze event in October or November. An individual inflorescence flowers for about 7-10 days, depending on temperature, but new flowers are made during the entire growing season. Female fertility of flowers is very low, and the new cultivar sets limited seed in a field or landscape setting, an asset in landscape plantings.
‘Lilac Chip’ is distinguished from other related known cultivars based on the unique combination of traits including very dwarf growth, spreading habit, purple pink flowers, male sterility, and very low female fertility.
The new variety has been named the ‘LILAC CHIP’ cultivar. First public offer for sale of ‘Lilac Chip’ was made in Grand Haven, Mich., U.S.A. on Aug. 1, 2011.